Metal oxide nanocrystals have attracted extensive interest due to their unique chemical, physical, and electrical properties. Certain materials are known that are both electrically conductive and optically transparent to incident light. One type of this material, a transparent conducting oxide (TCO), is formed by an oxide of one or more metals.
Owing to their optical and electrical properties, TCOs have found use in a variety of applications. One such application is to serve as an electrode of a liquid crystal display (LCD). Other applications utilizing TCOs include solar cells and touch screens.
A commonly-used TCO material comprises indium tin oxide (ITO). ITO nanocrystals have been used to fabricate ITO sputtering targets, which are the main sources to make ITO thin films. Other processes to make ITO films include depositing ITO nanocrystals on the substrate via a solution approach. In general, these two methods to make ITO films call for ITO nanocrystals having regular shapes and uniform sizes with a relatively narrow distribution.
To prepare metal oxide nanocrystals with regular shapes and uniform size, a thermolysis method has been widely used. This method requires large amount of organic solvent and expensive metal-organic precursors for certain kinds of metal oxides. Accordingly, there is a need in the art for novel methods of preparing metal oxide nanocrystals efficiently and economically.